Contaminant Control in High-Performance Buildings Project

Summary:

Net-zero energy strategies have the potential to significantly impact the indoor air quality of buildings. This project is designed to better understand how strategies to achieve net-zero energy and sustainable buildings will impact the concentrations of high-priority indoor air contaminants and to support the development of effective low-energy solutions that also improve the health of indoor environments. Specific project outcomes include improved field test methods for measuring the generation and transport of ultrafine particles and formaldehyde in buildings, reference materials and standards for product emissions testing, and performance measures for low-energy ultrafine particle controls.

Description:

Objective: To develop test methods, reference materials, and innovative low-energy contaminant control strategies, and enable their integration into building design and retrofit guidance, standards, codes, and building material emissions labeling programs by FY2015.

What is the new technical idea? NIST is developing the measurement science required to support strategies that maintain or improve indoor air quality (IAQ) in high-performance buildings. Changes that are being made in the design, operation and furnishing of buildings to save energy and promote sustainability (e.g., envelope insulation and tightening, alternative ventilation approaches, and installation of “green” building materials) have the potential to alter the indoor environment, with the potential to adversely affect the health and productivity of building occupants.1,2 NIST is focusing on how building and system designs impact contaminants of particular concern,3 specifically ultrafine particles (UFP) from indoor and outdoor sources, and formaldehyde and other volatile organic compounds (VOCs) and semi-VOCs (SVOCs) from building materials and products.

NIST is also developing measurement tools needed to support the development of low-energy control solutions that can lead to reductions in building ventilation requirements. Specifically, the use of building materials with low VOC emissions may allow energy savings by lowering outdoor air ventilation requirements. To support improved labeling of low VOC products, NIST is developing reference materials with known contaminant emissions profiles and standard residential exposure scenarios to assess the installed impact of these products. Other energy-efficient contaminant control options that are being investigated include enhanced filtration, local exhaust, and building envelope designs to reduce exposure to ultrafine particles.

What is the research plan? The research plan addresses the performance of IAQ controls for reducing contaminants and building energy requirements. The first objective of the plan addresses a contaminant of national importance: ultrafine particles (UFP)4. In FY13 NIST conducted studies to understand the removal of UFP from buildings using electrostatic precipitators (ESPs). In FY14, this work will be expanded to examine UFP removal using media filters as well as the development of a standard test method to quantify capture efficiencies of kitchen exhaust systems. In addition, NIST will work within ASTM D22.05 on Indoor Air Quality to support project goals, including filtration and indoor carbon dioxide standards.

For VOCs and formaldehyde, the most effective control strategy is to reduce emissions from building products and materials. To improve the reliability of emissions testing, NIST has been developing reference materials in collaboration with Virginia Tech and EPA. In FY13 research was conducted to prepare a toluene reference material for production and distribution, and prototype reference materials for formaldehyde were investigated in support of EPA regulations on emissions from wood products. In addition, a draft standard guide for assessing emissions measurements from standard reference materials was developed under ASTM D22.05. In FY14 a NIST Quality System for the toluene reference material will be developed and the development of a formaldehyde reference material will be pursued based on the needs identified by EPA. These reference materials will allow manufacturers and designers to estimate indoor contaminant levels associated with different product choices and support existing and future product labeling programs.

In the area of indoor emissions from SVOCs, EPA and CPSC (Consumer Product Safety Commission) have concerns about emissions from spray polyurethane foam (SPF), which is increasingly being used to improve building energy performance. Microchamber equipment was installed in FY13 to support the development of SPF emissions test methods and product use guidelines. In FY14, methods will be developed to use the microchambers for measuring the emissions of aldehydes and amines from SPF products in support of CPSC programs. Related activities within ASTM D22.05 will also include the development of standards for preparing SPF samples and emissions measurement.

[4] National Science and Technology Council (2008), National Nanotechnology Initiative: Strategy for Nanotechnology-Related Environmental, Health, and Safety Research, Executive Office of the President: Washington, D.C.

Major Accomplishments:

Outcomes:

The further development of the toluene reference film. Packaging challenges were addressed to move the material closer to production phase.

Exposure scenarios were developed in conjunction with ASTM and the California Department of Public Health (CDPH) to assist in evaluating acceptable VOC emission rates in building products.

In-duct electrostatic precipitator (ESP) experiments showed that these devices are ineffective at removing nanoparticles (3-10 nm) and revealed the propensity of these devices to emit significant levels of ozone.

Impact of Standards and Tools:

Reference VOC source developed which is to serve as a NIST Standard Reference Material.

Using NIST’s small chamber test facility, researchers are assessing the performance of a prototype reference material to improve the measurement of volatile organic compound emissions from building products.